In submergible crude oil pumping systems, the system's components including the pump, motor, tubing, and related mechanical features are disposed within a well casing in a bore hole typically in or beneath the oil well underground, commonly at distances from 1-2 kilometers under the earth's surface.
It is quite common for some of this equipment to break down during operation, requiring work stoppage and repair, or the introduction of new pumping systems into the bore hole. Engineers and oil service companies are constantly reviewing pumping systems and related operations to improve their efficiency and reliability.
One area of review to improve the efficiency and reliability of the pumping systems is the electrical supply system. The electrical supply for such pumping systems typically includes up to 4 kv power supply, with three separate phases of power being included in one electrical power supply to the pumping system. The electrical power supply has been one of the weakest points of electrical submergible pumping systems. As a result, more failures related to the electrical power supply have been reported during field operations. Due to the environment that these systems operate in, the oil, sand, rock, etc. either degrade the protective covering around the electrical conductor or are sharp enough to break the protective cover's barrier leading to a failure of the electrical supply leading to a motor damage, an explosion, furthermore, breakdown of the whole submergible pumping systems. The electrical system for the motor in the pumping system requires a reasonable space for reliability of connection, insulation, and sealing. In many applications, the down hole space is very limited.
Therefore, there is a need for more efficient and reliable electrical supply to motors associated with the pumping systems.